Ethereum openly admitted that they're dumping massive amounts of coins. I think around 20k btc. The dump will just eat up all the buy orders, so btc price won't rebound at least until the dump is complete. It might just so happen the dump is happening on btc-e.
I thought they were selling closer to 2k coins? I could be mistaken but I am pretty sure this is the more accurate number. I would argue that the price dropping so much was due to the fact that btc-e likely made their margin requirements more strict and by doing so created a very large margin call across many accounts.